Improving Access to International Collections of Earth Observation Data
In support of its role as the satellite arm of the Group on Earth Observation (GEO) Global Earth Observation System of Systems (GEOSS), the Committee on Earth Observation Satellites (CEOS) Working Group on Information Systems and Services (WGISS) has initiated a project to provide a common access pathway to the data collections of the CEOS member agencies. CEOS participants are representatives from the international agencies that operate Earth observing satellites and affiliated organizations that use the agency data products. Collectively these Earth observation products represent a tremendous resource that can be utilized by numerous efforts of the GEO societal benefit areas but there are barriers to the effective discovery and access of the products. Each agency has developed its own systems to manage and distribute these data but they typically are based on their own set of data systems standards and conventions and not necessarily those promoted within the GEO community.
The CEOS WGISS Integrated Catalog Project (CWIC) is addressing these barriers by developing a brokering service that will provide a common mechanism to discover and access all of the collections of the participating CEOS members. The CWIC architecture and current participants are shown in the following figure.
CWIC is being implemented following the OGC/ISO Catalog Service for the Web (CSW) Version 2.0.2 that is the GEO adopted standard and will be able to respond to searches from GEO and other clients that follow that standard. CWIC is working with a previous WGISS effort, the International Directory Network (IDN), to provide dataset discovery and collection level metadata to CWIC clients. The CWIC team is working with agency representatives of each participating data partner to develop a connector that will translate the search/response dialog between the CSW clients and standards of the local data systems. These connectors allow users to identify and access those data products that meet their specific needs.
The CWIC project is currently in its third year of development and while it has successfully implemented and demonstrated a basic set of capabilities, significant challenges lie ahead. The demonstrations have captured the interest of additional data partners and potential clients resulting in increased demands on a limited development team. At the same time, the team is working with current data providers to explore the issues associated with user registration and authorization in a federated system and also the needs for enhanced metadata to support data discovery and search. Additionally, to truly provide a GEO core capability the CWIC project must begin to address the transition from a technology prototype to a sustained, operational component of GEOSS.